Paint and varnish remover



Patented July 11, 1933 UNITED STATES PATENT OFFICE MELVILLE M. WILSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SHABPLES SOLVENTS CORPORATION, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF DELA- WARE No Drawing.

This invention relates to compositions for the removal of paint and varnish from surfaces or materials to which they have been applied, and particularly to a composition for removing dried or hardened paint and varnish by softening or dissolvin the same. Varnish and paint removers of t e type to which this invention relates are substantially free of water and alkali.

It has been proposed to prepare varnish and paint removers of the type to which this invention belongs, by including in the varnish and paint remover a substance or substances capable of dissolving or cutting or softening the dried or oxidized oil or the dried resins, or both of such ingredients, of dry paint and varnish. However, such dissolving or softening or cutting agents heretofore used are so highly volatile when used alone that uneconomical quantities are necessary to do the work, and it has been proposed to add paraffin wax to the remover in order that it will form a superficial protective film and delay evaporation of the dissolving or cutting or softening agent sufficiently to permit an economical quantity of that agent to perform its function before it evaporates; p

The wax so employed is not only an inert ingredient so far as concerns the softening, dissolving or cutting action of the remover, but it forms a coating upon or 'becomes absorbed into or impregnates the surface stripped of paint or varnish and impairs the suitability of the stripped surface for the reception of a fresh coating of paint or varnish. If such a surface is coated with lacquer, the wax remaining thereon or absorbed therein causes softness and prevents adherence of the freshly applied lacquer. It was proposed to remove such residual wax by washing the stripped surface with naphtha but complete removal of the wax can not be effected in that way.

It is an object of this invention to provide a paint and varnish remover that is readily compounded and is efiicient in operation and is economical in use. A feature of my invention is that paint and varnish remover made in accordance therewith con- PAINT AND vnmrsn movnn Application filed February 15, 1929. Serial No. 340,330.

tains ingredients of such nature that it may be composed entirely of ingredients that are active in the removal of paint and varnish and no harmful inactive ingredient need be included. A further feature of my invention is that paint and varnish remover made in accordance therewith contains ingredients that cooperate with one another to effect more rapid softening or dissolving or cutting of the paint or varnish than is effected by separate use of the ingredients when they are economically employed. A further feature of my invention is that varnish and paint remover made in accordance therewith will not when employed in economical quantities evaporate from the paint ed or varnished surface before the paint or varnish is sufficiently dissolved or softened or cut, and it will leave the stripped surface in a condition suitable for recoating.

I have found that liquids which are chloride substitution products of saturated hydrocarbons are active in the removal of paint and varnish and that such chlorides form, with other agents that act to dissolve or soften or cut paint and varnish films, mixtures of such character that they are well suited for practical use as paint and varnish removers; and that the wide range of boiling points of such chlorides makes it possible to select one or more of them having such a boiling point or boiling points as to ensure that the chloride so selected, and also other ingredients used therewith, will not evaporate until the desired cutting action has taken place but will evaporate with sufficient rapidity to ensure that the stripped surface will be free of such chlorides and other ingredients within a convenient working period and will be in a condition well suited for re-coating. In this connection I have found that such chlorides, that term including mono-chlorides and poly-chlorides herein, act rapidly in the cutting or dissolving or softening of resins and also areactive in the cutting or softening or dissolving of dried or oxidized oils.

I have found that when such chlorides are mixed with one or more of such substances as alkyl-benzenes or aromatic hydrocarbons 9 cut dried or oxidized oils in paintand varof the type of benzene, alcohol, and phenols,

the mixture is of such nature that it is well.

adapted for use as a paint and varnish remover and the ingredients thereof cooperate with one another to effect more rapid softnish films with fair rapidity and also exert a cutting action on resins in such films, and when mixed with a larger proportion of such chlorides the resulting mixture effects the desired cutting action more rapidly than either such chlorides or the alkyl-benzenes or aromatic hydrocarbons of the benzene type when those substances are used alone. Alcohols cut resins with fair rapidity and exert some cutting action on dried or oxidized oils and when mixed with a larger proportion of such chlorides the resulting mixtures effects a desired cutting more rapidly than eithet' the chlorides or the alcohols used alone. In

some cases a mixture of such chlorides with alkyl-benzenes or aromatic hydrocarbons of the type of benzene may not operate efficiently in the removal of paint, and mixtures of such chlorides with alcohols may not operate efficiently in some cases in the removal of varnish, and I have found that a threeconstituent mixture consisting of such chlorides and a preferably lesser proportion of alkyl-benzenes or aromatic hydrocarbons of the type of benzene, and a similar preferably lesser proportion of a lower boiling alcohol, effects a sufficiently complete cut ting or softening of paint and varnish in less time than is required by a-mixture of such chlorides with only alkyl-benzenes or aromatic hydrocarbons of the type of benzene or with only alcohol. I have also found that if there is added to such a three-constituent mixture, a similar preferably lesser proportion of phenols, the cutting time on paint and varnish of the resulting four-constituents mixture is still less than the cutting time of such a three-constituent mixture. Also, a three-constituent mixture consisting of such chlorides and a preferably lesser proportion of phenols and a similar preferably lesser proportion of either alcohol or alkyl-benzenes or aromatic hydrocarbons of the type of benzene acts upon paint and varnish more rapidly than a two constituent mixture consisting of such chlorides and phenols.

Chlorides of hydrocarbons that may be used in the practice of my invention should be so chosen with respect to their boiling point that the varnish or paint remover made in accordance with my invention will not evaporate until the varnish or paint film to be removed is sufficiently dissolved or softened or cut-but will evaporate with sufficient rapidity to leave the stripped surface ready for re-coating in a. reasonable working time. The chloride so selected will depend upon the cutting time of the final mixture of chloride and'other ingredients. Examples of chlorides that may be employed among others in the practice of my invention are propyl, butyl, amyl, hexyl, and benzyl chlorides and chlor-benzol, and propylene, butylene, amylene, hexylene dichlorides and higher boiling chlorides. Ethyl chloride and ethylene dichloride are effective but have a relatively low boiling point and are only recommended in mixtures that cut rapidly or in connection with very thin films of paint or varnish to be removed.

Phenols that may be used in the practice of my invention include crude cresol, creosote oil, cresol, phenol and other substances included in crudecresol or creosote oil, and the term phenols is used herein to include any one or more of those substances.

Alkyl-benzenes or aromatic hydrocarbons of the benzene type that may be employed in the practice of my invention include, among others, toluol and xylol.

The particular one or more of such phenols and alkyl-benzenes or aromatic hydrocarbons of the benzene type that may be employed will be so chosen, and used in such proportion, that the resulting mixture will effect the desired cutting before evaporation and will leave the stripped surface ready for re-coating in a reasonable working period.

Various alcohols, such as methyl, ethyl, propyl, butyl and. amyl alcohols, may be employed in the practice of my invention but it is preferable that the alcohol employed shall be the lightest alcohol that has a sufiiciently high boiling point, ethyl alcohol being preferable in most cases.

As a specific example of the practice of my invention I have found that the cutting time, a

mixture last named has an evaporation time of 4 to 5 minutes at room temperature when applied in economical quantities per unit of surface area.

Further specific features of my invention may be of assistance in the practice and in the understanding thereof. A mixture consisting of a chloride and phenol constitutes a paint and varnish remover that acts more rapidly than either of its constituents, and while the use of creosote oil in such a mixture will cause the stripped surface to be ready for re-coating in less time than will the use of pure cresol, the phenol constituent of a paint and varnish remover made in accordance with this invention will usually determine the working time, i. e. the time that must elapse before recoating. For this reason it is recommended that the ingredients of a paint and varnish remover made in accordance with this invention shallbe so proportioned that phenols will not.constitute substantially more than 20% of the final mixture. To this end the use of benzene homologues and of alcohol in addition to the chloride employed, not only results in a mixture that acts more rapidly than any of the ingredients and that in many cases will not require the presence of phenol, but the use of either or both of such ingredients makes it possible to produce a highly effective paint and varnish remover that contains phenol but in which phenol constitutes a small proportion of the total mixture.

Thus, a mixture containing chlorides, phenols, benzene homologues and alcohol is not only more effective than a mixture contain ing only chlorides, phenol and alcohol or a benzene homologue, but it may contain a lower percentage of phenols. Moreover, a mixture of chlorides, benzene homologues and alcohol is very effective and leaves the surface ready for recoating in a short time and phenol needonly be added to obtain more rapid cutting action as in the removal of thick or very old coatings, the addition of phenol causing the cutting action to be more rapid than the cutting action of phenol alone or of any of the other ingredients of the mixture when used alone,

From the foregoing it is apparent that I have provided a varnish and paint remover which can he so compounded that all ingredients thereof are active in the cutting, dissolving or softening of paint and varnish, and which is free of water and alkali and wax and other substances that undesirably impair or roughen, or render unsuitable for recoating any surface cleaned thereby, and which can be so compounded, by varying the ingredients and the proportions thereof, that the paint or varnish to be removed can be sufficiently softened before an economical uantity of the mixture is evaporated, and t e properties of which can be varied to suit varying requirements. In the compounding of a paint and varnish remover in accord ance with my invention highly effective ingredients may be employed in spite of their high volatility because unduly rapid evaporation thereof can be prevented by select ing a chloride or polychloride that is not only of sufiiciently high boiling point to retard the evaporation rate but is in itself a removing agent. In the claims a reference to a volatile substance or mixture means a substance or a mixture that evaporates under atmospheric conditions with sufficient rapiditv to cause a wooden surface coated therewith to be substantially free of the substance or of every ingredient of the mixture within'a period of time not greater than approximately an hour after the coating is applied.

I claim:

1. A paint and varnish remover comprising a volatile paintand varnish-softening agent, and amylene dichloride.

2. A paint and varnish remover comprising. a volatile paintand varnish-softening agent, and a polychlor derivative of a saturated paraffin hydrocarbon having three to six carbon atoms.

3. Apaint and varnish remover comprising a polychlor derivative of a saturated paraffin. hydrocarbon 'having three to six carbon atoms and one of the group of substances consisting of phenols, benzene homologues and alcohols.

4. A paint and varnish remover compris- -ing amylene dichloride, a phenol, and

alcohol and a benzene homologue.

5. A paint and varnish remover comprising amylene dichloride, toluol and alcohol.

6. A paint and varnish remover comprising amylene dichloride, toluol and a phenol.

7. A paint and varnish remover comprising amylene dichloride, alcohol and a phenol.

8. A paint and varnish remover comprising amylene dichloride, and a phenol.

9. A paint and varnish remover comprising amylene dichloride and substantially smaller volumes of toluol, of alcohol, and of cresol.

10. A paint and varnish remover comprising two parts by volume of amylene dichloride, one part by volume of toluol, one part by volume of ethyl alcohol, and one part by volume of cresol.

11. A paint and varnish remover comprising a volatile paint and varnish softening agent, and propylene, dichloride.

In testimony whereof, I have signed my name to this specification.

MELVILLE M. WILSON. 

